Self-opening paraffin knife for tubing



April 19, 1960 w. H. BRITE 2,933,138

SELF-OPENING PARAFFIN KNIFE FOR TUBING Filed April 10, 1957 Fig.

Fig.5 Z8 40 W/Yber H. Br/fe 32 IN VEN TOR.

Unite 1 States Patent 2,933,138 SELF-OPENING PARAFFIN KNIFE FOR TUBING Wilber H. Brite, New Orleans, La.

Application April 10, 1957, Serial No. 651,922 Claims. (Cl. 166-174) This invention comprises a novel and useful selfopening paratfin knife for tubing, and more particularly relates to a paratiin cutter especially adapted for treating paraffin deposits from the interior of tubings, casings, well bores or the like.

The principal object of this invention is to provide 'a parafiin cleaner which may be readily inserted into the interior of well tubing, well casings, or well bores for effectively cleansing paraffin deposits from the interior thereof whereby to restore the normal rate of flow through such tubing, casing or bore.

A further object of this invention is to provide a paraffin cleaner wherein the cleansing action of the same may be effected uniformly about the entire circumference of the device.

A still further object of the invention is to provide a parafiin cleaner in accordance with the foregoing objects which may be readily applied to a string for insertion into and for removal from a tubing or the like, whereby the knife elements of the device may be normally moved into a collapsed position to permit insertion of the device into a tubing or the like, and whereby the knife elements may be readily expanded into an operative cutting position upon a withdrawing movement of the device from tubing or the like.

Yet another important object of the invention is to provide a parafiin cleaner in accordance with the above mentioned objects which shall include means limiting movement of the knife elements to their open position.

And a final important purpose of the invention is to provide a paraffin cleaner as set forth in the above mentioned objects wherein the cleaning knives may be very economically constructed of an inexpensive material such as stiff wire and may be mounted in an improved manner upon the body of the cleaning tool.

'Ihese, together with other objects and advantages which will become subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which: i t

Figure 1 is an elevational .view showing a suitable embodiment of the paraflin cleaner incorporating therein the principles of this invention and showing the knives of the cleaner in their operative position;

Figure 2 is an end elevational view of the tool of Figure 1 showing the circumferential disposition of the series of knives about the longitudinal axis of the tool;

Figure 3 is a view in vertical section through a portion of a well tubing, and showing the manner in which the paraffin cleaner operates to strip parafiin deposits from the interior of the tubing;

Figure 4 is a view similar to Figure 3 but showing the manner in which the parafiin cleaner is introduced into a tubing for removing incrustations therefrom, with a knife element of the device being shown in its collapsed position for introduction-into the parafiin-incrusted tubing; and

Figure 5 is a perspective view of the construction of a knife element forming a part of the tool.

It is a common problem in the producing of oil from formations by flow of the oil through the tubing of an oil well to contend with the deposits of parafiin which form incrustations upon the interior walls of the tubing during the flow of oil therethrough. As these deposits build up, the flow of oil is materially reduced or throttled until eventually further operation of the well becomes economically unsatisfactory or mechanically impossible. When this condition arises, it is necessary to remove the incrustations of paraflin before operation of the well can be continued.

Prior attempts to remove such parafiin deposits have frequently employed the use of a parailin scraper or cutter, carried by a string of rods or the like, and which is pushed down the tubing string for cleansing the parafiin deposits from the interior thereof. 7

t It is the purpose of this invention to provide a device wherein the blades or scraping elements of the paraflin cleaner may be easily introduced into a tubing stringto the bottom thereof, and may then be expanded into a paraffin cutting position whereby they may be effected for cleansing parafiin from the interior of the tubing when the device is pulled upwardly through the same. Cleansing a tubing string in this manner requires a less expenditure of power and is more readily performed than the above referred to conventional practice.

In the embodiment illustrated in the accompanying drawings as an exemplification of the principles of this invention, the paraffin cleaner comprises: an elongated rod-like body 10 which may conveniently be square in cross-section and which, at its upper end, is secured in any suitable manner to the lower end portion 12 of a string such as a sucker rod string by means of which the tool may be lowered into the tubing of a well bore and may be removed therefrom. Alternatively, a Wire line may be employed in place of the string 12 inasmuch as the device may be readily inserted into a tubing string by gravity without the necessity for any effort being applied for forcing the device downwardly through the tubing to the bottom thereof.

Shown in Figures 3 and 4 is a section designated by the numeral 14 of a string of tubing which has accumulated an incrustation of paraffin as shown at 16 and which it is desired to remove in order that flow through the tubing may be restored to the desired original Volume.

Referring first to Figure 1, it will be seen that the rod-like body 10 is twisted about its longitudinal axis to provide three circumferentially angularly disposed aligned sections such as those indicated at 18, 20 and 22. While any desired angular relation of these sections may be employed, it is preferred to dispose these sections at equal angular intervals.

Mounted upon each of these sections are a plurality of novel knife constructions each of which is designated tending entirely through the body 10, or alternatively" may consist of oppositely aligned bores or recesses extending into the body from opposite faces thereof. In any event there are thus provided oppositely disposed bores or recesses on opposite sides of the body into each pair of which recesses the knife element 24 is operatively mounted as set forth hereinafter.

Referring now especially to Figure 5, it will be seen that each of the knife elements 24 preferably comprises a member formed of a single piece of Wire or similar material. shaped portions having their legs angularly disposed and integrally connected. Thus, the larger U-shaped portion consists of anend member 26 consisting of a straight piece of material, with a pair of legs 28 and 30 extending Each element 24 comprises a pair of U therefrom. The other and smaller U-shaped portion comprises an end member 32 with a pair of legs 34 and 36 extending therefrom. The legs 28 and 34 are joined by inturned extremities each designated by the numeral 38, while the legs 30 and 36 are joined by similar inturned spect to elongated body portion 10. As will be observed from Figure 1, there are four such blades disposed on each of the sections 18, 2t) and 22, whereby there are a pair of oppositely disposed blades for each of the opposite surfaces of that section. The lengths of the U-shaped sections of each blade are such that when the blades are mounted as. shownin Figures 3 and 4, the smaller U- shaped section is adapted'to'e'mbrace the body portion 18, 201 or 22 and if desired may limit closing movement of the blades, this being the movement in the direction indicated by the arrows 42 and 44 to the position shown in Figure 4. This will be the position normally assumed by. the blade as the tool is moved downwardly in the tubing as shown by the arrow 46. This may be considered to be the closed or collapsed position of the blades.

However, the larger Ushaped portion of the blades will by its gravity tend to open the blades to the position shown in Figure 3, and which is the position whereby the ends 26 of the blades will engage the interior of the tubing'14 and scrape the parafiin incrustation 16 therefrom. when the tube is withdrawn as shown by the arrow 48 in Figure 3.

If desired, the length of the legs 34 and 36 of the smaller U-shaped portion may be such as to cause the end portion 32 thereof to abut the body and thus limit both the opening and the closing pivotal movement of the blades. However, it is preferred to provide cross bars 50 welded or otherwise secured to the opposite sides of the body 10 to constitute stops, as shown in Figure 3, tolimit the opening movement of the blades.

By the longitudinal spacing of the blades along th three circumferentially twisted sections of the elongated body, there is provided for each section a cutting blade having a cutting edge 26 disposed in each of the four surfaces of that section of the body, whereby, as shown in Figure 2, all of the cutting edges 26 will overlap to thus scrape paratfin from the entire interior circumferenceof the tubing.

It; will be understood that this construction may also be employed to scrape parafiin from the interior of a casing or even from the wall of a well bore in some instances.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur'to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A parafiin cleaner for scraping paraflin accumulations, from the interior of tubings or casings and well bores comprising an elongated body adapted for insertion and longitudinal travel in a tubing or casing, a plurality of longitudinally spaced, diametrically disposed bores in opposite sides of said body, a plurality of scraper blades each comprising a pair of U-shaped rod-like sections rigidly joined at their legs and having pivot members secured at their leg joints received in said bores for pivotal movement between a position wherein at least one of said sections is collapsed against said body for insertion in a string of'tubing and an extended position for scraping paraflin from the wall of a tubing string when drawn through the latter, the legs of said scraper blades being at least of a sufficient length to' extend from said pivot members to the interior wall of the tubing in which the cleaner is disposed, the legs of each scraper being so arranged that when. one section. contacts the tubing wall, the other section will engage said body and prevent pivoting of the blade past a' position in which it engages. the tubing wall. r

2. The combination of claim 1 wherein saidelongated body has a plurality of circumferentially angularly disposed sections, a plurality of blades mounted on each section whereby to'cover substantially the entire circum ference with overlapping blades;

3. The combination of claim 1 including a plurality of'transverse bars each secured to said body adjacent one of said blades and providing a stop engageable with a blade for limiting pivotal movement of said blade in its joined ends disposed in side-by-side relation and comprising said pivot members.

7. The combination of claim 1 wherein each bladecomprises a single piece of wire.

.8. A parafiin cleaner for scrapingparaffin deposits from the interior of a conduit comprising an elongated h-body, each blade including an open U-shaped section of rod-like character having a pair of legs disposed in sideby-side relation on opposite sides of said body and a web portion connected to said legs and extending therebetween and comprising a scraping element engageable with the wall of said conduit, said pair of legs being of a length at least equal to. the distance of their pivot point to the interior wall of said conduit, said body having oppositely disposed diametrical bores, saidlegs having inturned portions comprising pivot means received in said bores, said blades'being pivotable about said pivot means between an extended position in which said web is engageable with said conduit and a retracted position with said web disposed against said body, a stop bar extending transversely of andisecuredto the body adjacent each of said blades in position for engagement by the legs of said blades overlapping whereby to scrape the entire circumference of said conduit.

10. The combination of claim 8' wherein said blades each include a second U-shaped. section disposed on the opposite side of the body from the first mentioned section and rigidly secured to the latter, said second section having its legs shorter than those of the first mentioned sectiori'whereby the web of said second section will contactsaid elongated body and prevent the secondsection from swinging past the dead center positions of said.

sections. References Cited in the file of this patent UNITED. STATES PATENTS, 7

1,573,697 Crosby Feb. 16, 1926 3, 83 Spencer Dec. 27, 1927 .069 McKean et al. Mar. 30, 1943 

